You run a paint booth. Solvent vapors build up around the workpiece every time someone pulls the trigger on a spray gun. The code calls the area within 5 feet of the workpiece Class I, Division 1, and the 3-foot zone around the booth's openings Class I, Division 2. Pick the wrong fixture and your install fails ESA or RBQ inspection — or worse, ignites. Here's the short version of what to spec, and what it actually costs in Quebec and Ontario.
What hazard you're dealing with
Spray solvents (acetone, toluene, xylene, MEK, most automotive paints) put out flammable vapors heavier than air. Around the workpiece during spraying they're above the lower explosive limit. Outside the booth opening, vapors drift but burn off fast — so the hazard is "abnormal" rather than "continuous." Both zones need fixtures certified to not be the ignition source.
How the code classifies your booth
| Where | Classification | What you need |
|---|---|---|
| Within 5 ft horizontal + 5 ft vertical of the workpiece | Class I, Division 1, Group D | Explosion-proof fixture, UL 844 / CSA C22.2 No. 137 |
| Within 3 ft of any booth opening (closed-top booth) | Class I, Division 2, Group D | Vapor-tight or explosion-proof, T4 minimum |
| Within 20 ft horiz / 10 ft vert of an open spraying operation (no booth) | Class I, Division 2, Group D | Vapor-tight or explosion-proof |
| Booth interior outside the Div 1 envelope | Class I, Division 2 | Vapor-tight LED |
| Outside the classified zones | Unclassified | Standard industrial LED |
NFPA 33 sets these zones. CEC Section 18 enforces the equivalent in Canada. Most operators standardize on Class I Div 1 fixtures throughout the booth interior to simplify spec and inventory — that's overspec but always passes inspection.
The lighting
- Fixture type: Class I Div 1 linear LED (4 ft or 8 ft) inside the booth, mounted behind sealed glass. Vapor-tight LED for the Div 2 perimeter.
- T-code: T4 minimum (135 °C max surface). Most automotive paint solvents auto-ignite around 200 °C — T4 buys safety margin.
- IP / NEMA rating: IP66 / NEMA 4 minimum so overspray doesn't ruin the optic.
- Light level: 750–1,500 lux for general spraying. 2,000 lux if you do paint-mix comparisons under the booth lights.
- CRI: 90+ is non-negotiable for color-critical work. Cheap LEDs at CRI 70 will make a perfect match look wrong on delivery day.
- CCT: 5000 K daylight for color accuracy. 4000 K if your customer is OK with neutral white.
Cables & accessories — yes, we supply these too
Your electrician will run TECK90-HL or MC-HL cable into the booth, with CSA C22.2 No. 174 cable glands at every penetration and sealing fittings within 18 inches of the booth wall. Most lighting suppliers stop at the fixture — we don't. We'll spec the whole package: fixtures, cable, glands, sealing fittings, junction boxes, conduit. One PO, one delivery, one contact. If your contractor opens the box on install day and a gland is missing, we ship next-day from our network.
Quebec rule
In Quebec the RBQ enforces this through Code de construction, chapter V — Électricité (which adopts CEC Section 18). Bill 96 means the safety labels on the fixture must be in French — we ship Quebec orders with FR safety labeling. Hydro-Québec's Programme Solutions efficaces covers up to 90% of the conversion cost on commercial/industrial paint-booth retrofits.
Ontario rule
In Ontario the ESA enforces this through the OESC (CEC + Ontario Amendments). You'll need an ESA notification before install. Save On Energy's Retrofit Program (administered by IESO) covers up to 50% of eligible project costs for LED upgrades, including paint-booth retrofits.
Common questions
Can I use a Class I Division 2 fixture inside the booth? No. The booth interior is Division 1 during spraying. A Div 2 fixture inside the booth fails inspection.
What about LED lights mounted outside the booth, shining through glass panels? Allowed under NFPA 33 if the glass is fixed, sealed, and rated. The light source itself can be unclassified — but the fixture has to be on the unclassified side of the glass, not the booth-interior side.
Are LED lights actually explosion-proof? Yes, when the housing is built to UL 844 / CSA C22.2 No. 137 with a sealed enclosure that contains internal sparks. The LED isn't inherently safer than the housing.
Do I need to interlock my paint booth lights with the exhaust fan? NFPA 33 requires the spray operations to stop if exhaust fails — not strictly the lights. But many AHJs require the lighting interlock too, especially for cannabis-extraction-style installs. Check with your local inspector.
How many fixtures do I need for a 14×24 ft booth? Rough rule: aim for 1,000 lux at the work surface. Two 4-ft Class I Div 1 LED linears per side typically gets you there. Send us your booth dimensions and we'll do the layout.
Talk to a specialist
Spec'ing a paint booth project? Send us your line list — fixtures, cable, glands, seal-offs, junction boxes — we quote the whole package same day. Or browse Class I Division 1 linear fixtures if you've already got the rest sourced.
Sources: NFPA 33 (2024 ed.), CEC Section 18, ESA Bulletin 18-1-21, RBQ Classification des emplacements dangereux, Hydro-Québec Solutions efficaces, Save On Energy Retrofit Program, IES Lighting Handbook.
Spec'ing a project? We quote the whole package — fixtures, cable, glands, sealing fittings — same day.